XCOR and ULA Update

Time for an update on theprogress around the XCOR.   This puts the company firmly into the enginedevelopment business with the resources to build out hugely improved enginesfor the aerospace industry.  Checkprevious posts to see the past demonstrations. (google XCOR on this site.

We can expect to see a line ofengines with different power ratings come quickly although they are surely waitingfor a shoe to drop somewhere. It appears to this outsider to be goingwonderfully.

XCOR and ULA Demonstrate Revolutionary Rocket Engine Nozzle Technology;Also Sign Contract for Liquid Hydrogen Engine Development

  

XCOR test fires its Lynx 5K18 engine with lightweight aluminum nozzle;

United Launch Alliance(ULA) and XCOR to apply the nozzle and XCOR's liquid hydrogen

(LH2) pump technology to new LH2 engine development.  (PhotoCredit: Mike Massee / XCOR)

March 22, 2011, Centennial, CO, and Mojave, CA, USA: United Launch Alliance (ULA) and XCOR Aerospace announcedtoday their successful hot-fire demonstrations of a lighter-weight, lower-costapproach to liquid-fueled rocket-engine vacuum nozzles. The new nozzletechnology, which uses aluminum alloys and innovative manufacturing techniques,is projected to be less costly and save hundreds of pounds of mass compared tonozzles in use today in typical large upper-stage rocket engine systems.

Under a 2010 joint risk-reduction program by XCOR and ULA, ULA facilitated anaccelerated demonstration of the nozzle technology, which was developed inXCOR's Lynx reusable, suborbital-vehicle technology program. ULA sought todetermine the nozzle technology's applicability to future expendable launchvehicle programs. Earlier in the same risk-reduction program, XCOR demonstratedthe ability to pump liquid hydrogen (LH2) using cryogenic piston-pumptechnology it developed for the Lynx suborbital vehicle.

Based on the results of these successful technology demonstrations, ULA todayannounced a larger follow-on program with XCOR to develop a liquid oxygen(LOX)/LH2 engine.

Conceived as a lower-cost, risk-managed program compared to traditional enginedevelopment efforts, the multi-year project's main objective is to produce aflight-ready LOX/LH2 upper-stage engine in the 25,000 to 30,000 lbf thrustclass that costs significantly less to produce and is easier to operate andintegrate than competing engine technologies. If successful, the effort willlead to significantly lower-cost and more-capable commercial and US governmentspace flights delivered by ULA. 

"ULA understands that we have to offer competitive prices to ourgovernment and commercial customers along with the outstanding and unmatchedreliability they expect from us," said Dr. George Sowers, vice presidentof business development and advanced programs at ULA. "By working withXCOR, we see the potential to develop engines that offer the performance andreliability our customers need at a more affordable price."

XCOR Lynx 5K18 main engine being  prepped for a test series. 

The companies structured their LOX/LH2 engine development programwith multiple "go / no-go" decision points and performance milestonesto ensure a cost-effective and risk-managed approach to this challengingeffort. As demonstrated during prior ULA and XCOR joint engagements,XCOR's small-company environment facilitates rapid turnaround for build andtest cycles that drive innovative learning, while ULA's small company projectmanagement approach ensures their needs are met but does not stifle thecreative process or saddle XCOR with excessive paperwork burdens typical oflarge government contracts. In addition, ULA is helping to bolster the Tier 2and Tier 3 aerospace-industrial supply chain in the United States, which is critical to ensuring the United Statesaerospace sector remains competitive in the global marketplace.

"This announcement validates XCOR's business mantra of 'stayfocused on propulsion, Lynx and the customer' and ULA is a greatcustomer," said Andrew Nelson, Chief Operating Officer at XCOR. "Andwhen you have innovative, safe, low-cost and fully reusable technologies thatfly multiple times a day, those technologies will find other buyers, such asULA. Whether it is non-toxic thrusters, fully reusable main-engine propulsion,cryogenic flight-weight piston pumps, or non-flammable cryogenically compatiblecomposite tanks and structures - the future looks bright for XCOR."

The demonstrations announced today are from integrated engine/nozzletest firings with XCOR's Lynx 5K18 LOX/kerosene engine. The engine/nozzlecombination demonstrates the ability of the aluminum nozzle to withstand thehigh temperatures of rocket-engine exhaust over numerous tests, with nodiscernable degradation of the material properties of the alloys.  Thetests validated the design, materials and manufacturing processes used in thenozzle, and laid a foundation for scaling the design to EELV-sized engines. Theresults also demonstrate the reusability of the engine and nozzle combinationwhich is essential for low-cost, daily suborbital flights by the Lynx and othervehicles.

"We are honored to work with the great team of individuals at ULA,a Tier 1 aerospace supplier," said Jeff Greason, XCOR CEO. "Thecritical engine technology we're developing for ULA may one day launchsatellites, capsules and space stations for government and commercialcustomers. Customers such as the US Air Force, NASA, the NationalReconnaissance Office, Boeing and Bigelow Aerospace all stand to benefit fromthis partnership. For a rocket engineer, there is nothing more exciting thanfiring a new engine for the first time. We can't wait for the day when we firstfire the new hydrogen engine for ULA."

# # # # #

United Launch Alliance - 50-50 joint venture owned byLockheed Martin and The Boeing Company - is the nation's rocket company,bringing together two of the launch industry's most experienced and successfulteams - Atlas and Delta. ULA provides reliable, cost-efficient space launchservices for the Department of Defense, NASA, the National ReconnaissanceOffice and other commercial organizations. ULA program management, engineering,test and mission support functions are headquartered in Denver, Colo.Manufacturing, assembly and integration operations are located at Decatur, Ala.and Harlingen, Tex. Launch operations are located at Cape Canaveral Air ForceStation, Florida, and Vandenberg Air Force Base, Calif. For more information onthe ULA joint venture, visit the ULA website at www.ulalaunch.com.

XCOR Aerospace is located in Mojave, California. The company is in the businessof developing and producing safe, reliable and reusable rocket poweredvehicles, propulsion systems, advanced non-flammable composites and otherenabling technologies. XCOR is currently working with aerospace primecontractors and government customers on major propulsion systems, andconcurrently building the Lynx, a piloted, two-seat, fully reusable, liquidrocket-powered vehicle that takes off and lands horizontally. The Lynxproduction models (designated Lynx Mark II) are designed to be robust,multi-commercial mission vehicles capable of flying to 100+ km in altitude upto four times per day and are being offered on a wet lease basis. (www.xcor.com)

PreColumbian Landscape Modification

This work demonstrates animportant research tool.  I would like tosee it extended to a number of geographically separated water sheds and to seethe work extended back several thousands of years in time.

We should be able to establishthe onset of corn culture and perhaps even determine the size of localpopulations with this approach provided we collect enough data to get excellentresolution.

There are plenty of questionsthat need to be answered with something more than a slew of undiscovered andeven undiscoverable habitation sites. Perhaps high schools could be recruited into the sampling program.

Agriculture disturbs naturalsedimentation rates.  Let us take fulladvantage of this information.

Native Americans Modified American Landscape Years Prior To The ArrivalOf Europeans

by Staff Writers

Waco TX(SPX) Mar 23, 2011

http://www.seeddaily.com/reports/Native_Americans_Modified_American_Landscape_Years_Prior_To_The_Arrival_Of_Europeans_999.html

A new study by Baylor University geologyresearchers shows that Native Americans' land use nearly a century ago produceda widespread impact on the eastern North American landscape and floodplaindevelopment several hundred years prior to the arrival of major Europeansettlements.

The study appears on-line in the journal Geology.

Researchers attribute early colonial land-use practices, such asdeforestation, plowing and damming with influencing present-day hydrologicalsystems across eastern North America. Previousstudies suggest that Native Americans' land use in eastern North America initially caused the change in hydrological systems,however, little direct evidence has been provided until now.

The Baylor study found that pre-European so-called "natural"floodplains have a history of prehistoric indigenous land use, and thuscolonial-era Europeans were not the first people to have an impact on thehydrologic systems of eastern North America.

The study also found that prehistoric small-scale agriculturalsocieties caused widespread ecological change and increased sedimentation inhydrologic systems during the Medieval Climate Anomaly-Little Ice Age, whichoccurred about 700 to 1,000 years ago.

"These are two very important findings," said GaryStinchcomb, a Baylor doctoral candidate who conducted the study. "Thefindings conclusively demonstrate that Native Americans in eastern North America impacted their environment well before thearrival of Europeans. Through their agricultural practices, Native Americansincreased soil erosion and sediment yields to the Delaware River basin."

The Baylor researchers found that prehistoric people decreasedforest cover to reorient their settlements and intensify corn production. Theyalso contributed to increased sedimentation in valley bottoms about 700 to1,000 years ago, much earlier than previously thought.

The findings suggest that prehistoric land use was the initial cause ofincreased sedimentation in the valley bottoms, and sedimentation was lateramplified by wetter and stormier conditions.

To conduct the study, the Baylor researchers took samples along the Delaware River Valley. Landforms were mapped based onrelative elevations to Delaware River baseflow and archaeological excavationsassessed the presence of human habitation.

The Baylor researchers then used a site-specific geoarchaeologicalapproach and a regional synthesis of previous research to test the hypothesisthat the indigenous population had a widespread impact on terrestrialsedimentation in eastern North America.

"This study provides some of the most significant evidence yetthat Native Americans impacted the land to a much greater degree thanpreviously thought," said Dr. Steve Driese, professor and chair ofBaylor's department of geology,College of Arts and Sciences, who co-authored the study. "It confirms thatNative American populations had widespread effects on sedimentation."

Asherah Edited From Bible

Biblical research is a gift thatkeeps on giving.  It is our one clearwindow into the lifeways of the Bronze Age and its culture.  Other scraps have survived, but none so completelyas that of the Bible unless we accept much older lineages for some of the IndianScriptures.  We should address that.

In the meantime, the originalpantheon consisted of Yahweh and Asherah which is mirrored by all the other pantheonsthroughout the Near East.  The cult of the one god appears to have beentolerated up to the Babylonian exile when the leaders chose to effectivelysuppress all other gods to create the modern Abrahamic religions.

The Levantacted as a religious crucible for the Mesopotamian – Hittite cults, TheEgyptian cults including Atan, and the Cult of Baal which appears to be atleast the Mediterranean Phoenician cult. We also have the Atlantean cult of Zeus and Poseidon identified.

It is startling to uncover ideasand practice that properly explain the often otherwise unexplainable.  Cross fertilization of these cults easilyproduce and even explain the most bizarre assertions.

I wonder how many prayers to Yahwehcan be profitably rewritten as a prayer to the mother goddess.

GOD'S WIFE EDITED OUT OF THE BIBLE – ALMOST

God's wife, Asherah, was a powerful fertility goddess, according to atheologian.

http://news.discovery.com/history/god-wife-yahweh-asherah-110318.html

By Jennifer Viegas 

Fri Mar 18, 2011 07:00 AM ET 

God had a wife, Asherah, whom the Book of Kings suggests was worshipedalongside Yahweh in his temple in Israel, according to an Oxford scholar.

In 1967, Raphael Patai was the first historian to mention that theancient Israelites worshiped both Yahweh and Asherah. The theory has gained newprominence due to the research of Francesca Stavrakopoulou, who began her workat Oxford and is now a senior lecturer in thedepartment of Theology and Religion at the University of Exeter.

Information presented in Stavrakopoulou's books, lectures and journalpapers has become the basis of a three-part documentary series, now airing in Europe, where she discusses the Yahweh-Asherahconnection.

"You might know him as Yahweh, Allah or God. But on this fact,Jews, Muslims and Christians, the people of the great Abrahamic religions, areagreed: There is only one of Him," writes Stavrakopoulou in a statementreleased to the British media. "He is a solitary figure, a single,universal creator, not one God among many ... or so we like to believe."

"After years of research specializing in the history and religionof Israel,however, I have come to a colorful and what could seem, to some, uncomfortableconclusion that God had a wife," she added.

Stavrakopoulou bases her theory on ancient texts, amulets and figurinesunearthed primarily in the ancient Canaanite coastal city called Ugarit, nowmodern-day Syria.All of these artifacts reveal that Asherah was a powerful fertility goddess.

Asherah's connection to Yahweh, according to Stavrakopoulou, is spelledout in both the Bible and an 8th century B.C. inscription on pottery found inthe Sinai desert at a site called Kuntillet Ajrud.

"The inscription is a petition for a blessing," she shares."Crucially, the inscription asks for a blessing from 'Yahweh and hisAsherah.' Here was evidence that presented Yahweh and Asherah as a divine pair.And now a handful of similar inscriptions have since been found, all of whichhelp to strengthen the case that the God of the Bible once had a wife."

Also significant, Stavrakopoulou believes, "is the Bible'sadmission that the goddess Asherah was worshiped in Yahweh's Templein Jerusalem. Inthe Book of Kings, we're told that a statue of Asherah was housed in the templeand that female temple personnel wove ritual textiles for her."

J. Edward Wright, president of both The Arizona Center for JudaicStudies and The Albright Institute for Archaeological Research, told DiscoveryNews that he agrees several Hebrew inscriptions mention "Yahweh and hisAsherah."

"Asherah was not entirely edited out of the Bible by its maleeditors," he added. "Traces of her remain, and based on those traces,archaeological evidence and references to her in texts from nations borderingIsrael and Judah, we can reconstruct her role in the religions of the SouthernLevant."

Asherah -- known across the ancient Near East by various othernames, such as Astarte and Istar -- was "an important deity, one who wasboth mighty and nurturing," Wright continued.

"Many English translations prefer to translate 'Asherah' as'Sacred Tree,'" Wright said. "This seems to be in part driven by amodern desire, clearly inspired by the Biblical narratives, to hide Asherahbehind a veil once again."

"Mentions of the goddess Asherah in the Hebrew Bible (OldTestament) are rare and have been heavily edited by the ancient authors whogathered the texts together," Aaron Brody, director of the Bade Museumand an associate professor of Bible and archaeology at the Pacific Schoolof Religion, said.

Asherah as a tree symbol was even said to have been "chopped downand burned outside the Templein acts of certain rulers who were trying to 'purify' the cult, and focus onthe worship of a single male god, Yahweh," he added.

The ancient Israelites were polytheists, Brody told Discovery News,"with only a small minority worshiping Yahweh alone before the historicevents of 586 B.C." In that year, an elite community within Judea wasexiled to Babylon and the Templein Jerusalemwas destroyed. This, Brody said, led to "a more universal vision of strictmonotheism: one god not only for Judah, but for all of thenations."

Largest Spam Source Shut Down

For long suffering internet usersthis is a little light at the end of the tunnel.    The close cooperation between Microsoft andthe USMarshalls is likely a harbinger of things to come.  Effective strategies to end this plague maywell be on the way.  Tossing the perps injail is certainly a good start and will plausibly send the small fry packing.

No one objects to legitimate advertisingor even targeted advertising if only because sometimes you want to be thetarget.  The spammer’s only clients areobviously criminal fronts for all sorts of doubtful product and free intrusive advertisingis their only way of penetrating the market. Besides, I am getting tired of hitting the delete button every day todispose of another Viagra offer or Nigerian fraudster.

Of course the worst aretransmitting out of country and we have to try harder with them.

The only reason I control commentaccess on this blog is to block multiple spam attempts which do appear at timesand they never quit in their efforts to bypass defenses.

World's biggest source of spam email shut down

The world's most prolific source of spam emails has been shut down in aseries of coordinated raids by Microsoft and US federal authorities.

http://www.telegraph.co.uk/technology/news/8391532/Worlds-biggest-source-of-spam-email-shut-down.html

Three Spanish men with 'limited' hacking experience are believed to bebehind the vast Mariposa botnet Photo: CLARE KENDALL

By Christopher Williams, Technology Correspondent 6:20PM GMT 18Mar 2011

The Rustock botnet, an international network of virus-infectedcomputers, had for years generated billions of emails per day, promotingunlicensed online pharmacies and cut-price impotence pills.

But on Wednesday, security firms noticed email traffic from Rustockcompletely collapsed. It has now been revealed that Microsoft, backed by USMarshals acting on a court order, seized servers that it's estimated covertlycontrolled almost a million Windows PCs.

“We think this has been 100 per cent effective," said RichardBoscovich, senior attorney in Microsoft's digital crimes unit, according to theWall Street Journal.

The servers were rented from commercial internet hosting firms acrossthe Mid West, who were apparently unaware of their role in Rustock. These"command and control" servers would issue instructions to infectedhome and business PCs worldwide.

The criminals behind the spamming business were named in Microsoft’slawsuit only as “John Does 1-11”. To get the court order, which empowered it toseize equipment and so "decapitate" the botnet, Microsoft alleged theJohn Does infringed its trademarks in some of their emails.

The scale of the shut down is unprecedented. A report last month bySecureWorks, a computer security firm, said Rustock was the world's biggestsource of spam.

“The reasons for this are due to the author’s relentless development ofstealth tactics,” it said, referring to how Rustock was frequently updated tostay one step ahead of anti-virus packages.

Superconductivity Established Near 20C

This is an update on previouswork and it appears that they have successfully reached the holy grail ofsuperconductivity research.  We have roomtemperature effects that could easily be fitted into a framework that neededmodest cooling at most.  Of course,turning all this into something that is commercially useful is quite anothermatter as we have seen with the materials finding their way into cryogenicsystems today.  Yet it has been done eventhere.

This is a classic example ofscience progressing at its best.  It hastaken over a century to reach this point from the initial recognition of thepossibility.  Hundreds, if not thousands,worked toward this day.  It is still not particularlycomplete but we are glimpsing the end of the tunnel.

As I have posted, the principlerequirement of a MFEV (magnetic field exclusion vehicle) is a thin layer ofsuperconducting material at as high a temperature as possible.  This is getting us there.  Simply producing hexagonal chips of suchmaterial could easily be assembled into such a structure.

Superconductivity Near 20 Celsius - Superconductivity Approaches RoomTemperature

17 March 2011

Superconductors.ORG

Superconductors.ORG herein reports the observation of superconductivitynear 20 C.

http://www.superconductors.org/20C.htm

       In eight magnetization testsa small amount of the compound (Tl5Pb2)Ba2MgCu10O17+ consistentlyproduced sharp diamagnetic transitions (the Meissner effect) near 20 Celsius(see above graphic), and resistive transitions that appeared near 18.5C (seebelow right). These temperatures are believed accurate +/- 2 degrees.

Resistance-v-temperature tests of this material were performed using a4-point probe. Four significant bits of data resolution were necessary toresolve the 18.5C critical transition temperature (Tc) due to a lowsignal-to-noise ratio (S/N). A sharp transition appeared across just 1.5 uA ofa 220 uA signal. This suggests a superconductive volume fraction less than 1%of the bulk.

       This extraordinarily high Tc wasachieved by engineering a theoretical D223 structure (where D=11 hex) thatpushes the limit of the longest C-axis lattice that will superconduct, whilesimultaneously establishing near-optimum Pb-doping of the Tl-Cu-O blockinglayers (see structure at left).

 In 2008 a Sn-In-Pb-Tm cuprateproduced superconductivity near 195K . That material had a C-axis latticeconstant around 33 angstroms. Attempts to go beyond 33 Å within that systemfailed to produce signs of superconductivity. That fact pointed to 33 Å being arough upper size limit for a superconductive unit cell within this family ofcopper perovskites. Since the 3 Celsius superconductor discovered in December 2010,had a C axis length under 28 Å, the next attempt to advance high Tc focused onincreasing the unit cell parameters. 

       The first material attempted was(Tl5Pb)Ba2MgCu9O15+ which had a C axis length near 30 Å, but a reducedpercentage of Pb doping - around 16%, sted 20% (see below 7C graphic). (Tl5Pb)Ba2MgCu9O15+ displayeda magnetic Tc near 9C (282K) and resistive Tc near 7C (280K). This was animprovement. However, within its magnetization plot were signs of still highersuperconductivity being generated by a minority phase.

 (Tl5Pb2)Ba2MgCu10O17+, with aunit cell near 32.7 Å, was then synthesized, displaying an unambiguousdiamagnetic transition near 20 Celsius.

       These 18C and 7C structures areshown below alongside the previous world record holders for comparison.

      With two atoms of divalent Pb, theinsulating layer of the 18C superconductor is hole-doped 28.5%. This increaseddoping level approaches the optimum of 25% discovered empirically within theSn-In-Pb copper-oxide family in 2008. Additionally, 28.5% is near a 30% optimumlevel for Pb-doping found by Shao, et al, in 1995(1).

       Dots have been placed within theC1 plot below, depicting where D223(Tl5Pb2-Mg) and B223(Tl5Pb-Mg) lie relativeto the other high performance thallium-cuprates. Temperatures plotted (inKelvin) are resistive. The correlation between planar weight ratio and Tc isunmistakable.

       As with prior discoveries thatadvanced high Tc through asymmetry along the C axis, this material does notform stoichiometrically (by conventional mixing of chemicals). It must besynthesized using the layer cake method, as shown below. The prototype pelletseach had roughly 20 to 22 layers. And, even using this technique, the volumefraction is low. Thus, commercialization will have to wait for a refinementmethod to be developed.

       This discovery is being releasedinto the public domain without patent protection in order toencourage additional research. Synthesis was by the solid state reactionmethod.

        The below stoichiometricratios were used for the ODD layers:

PbO 99.99%   (Alfa Aesar)   2.88 moles (gr.)

Tl2O3   99.99%   (Alfa Aesar)   7.366moles 

BaCO3   99.95%   (Alfa Aesar)  2.546 moles

CuO   99.995%   (Alfa Aesar)   4.106moles

       ...and the below ratios forthe EVEN layers.

MgO   99.95%     (Alfa Aesar)  1.04 moles (4x stoichiometric)

CuO   99.995%   (Alfa Aesar)   4.10 moles(4x stoichiometric)

       The chemical precursors werepelletized at 70,000 PSI and sintered for 35-36 hours at 865C. The pellet wasthen annealed for 10 hours at 500C in flowing O2. The magnetometer employedtwin Honeywell SS94A1F Hall-effect sensors with a tandem sensitivity of 50mv/gauss. The 4-point probe was bonded to the pellet with CW2400 silver epoxyand used 7 volts on the primary. Temperature was determined using an Omega type"T" thermocouple and precision OP77 DC amplifier.

RESEARCH NOTE: The copper-oxides are strongly hygroscopic.All tests should be performed immediately after annealing.

E. Joe Eck

© 2011 Superconductors.ORG

All rights reserved.

1. The Synthesis and Characterization of HgBa2Ca2Cu3O8+ Superconductors withSubstitution of Hg by Pb, by H.M. Shao, C.C. Lam, P.C.W. Fung, X.S. Wu, J.H.Du, G.J. Shen, J.C.L. Chow, S.L. Ho, K.C. Hung, and X.X. Yao, Physica C Volume:246, 1995 Page(s): 207-215 

Florida Tree Islands are Ancient Middens

Again we are continuing todevelop evidence of extensive human settlement throughout semi tropical Florida.  This was effectively confirmed by theearliest post Columbian penetration of these lands but those exploratory forayswere exploratory at best.  Thus we havescant information as indigenous populations promptly collapsed. 

Archeology is now establishingthe existence of uplifted midden based platforms that acted as likely townsites.  Obviously waste was tossed ontothe edges of the camps and the platforms grew steadily over thousands of years.

It is reasonable to presume thatshellfish was consumed daily by everyone as that was the local staple incoastal waters.  In fact, these localeswere well nigh impenetrable for anything but canoes and thus land game waslikely a rarity.  Thus fish and shellfishmust be consumed. 

As we know on the West coast,such a system can support huge populations were shell fish and salmon providedsustenance for communities of even ten thousand and produce huge middens.

Now we know were the hugepopulations in Floridaactually lived.

Ancient Trash Heaps Gave Rise To Everglades Tree Islands

by Staff Writers

Santa Fe NM(SPX) Mar 23, 2011

http://www.terradaily.com/reports/Ancient_Trash_Heaps_Gave_Rise_To_Everglades_Tree_Islands_999.html

Garbage mounds left by prehistoric humans might have driven the formation ofmany of the Florida Everglades' tree islands, distinctive havens of exceptionalecological richness in the sprawling marsh that are threatened by humandevelopment.

Tree islands are patches of relatively high and dry ground that dot themarshes of the Everglades. Typically a meter(3.3 feet) or so high, many of them are elevated enough to allow trees to grow.They provide a nesting site for alligators and a refuge for birds, panthers,and other wildlife.

Scientists have thought for many years that the so-called fixed treeislands (a larger type of tree island frequently found in the Everglades' mainchannel, Shark River Slough)developed on protrusions from the rocky layer of a mineral called carbonatethat sits beneath the marsh. Now, new research indicates that the real triggerfor island development might have been middens, or trash piles left behind fromhuman settlements that date to about 5,000 years ago.

These middens, a mixture of bones, food discards, charcoal, and humanartifacts (such as clay pots and shell tools), would have provided an elevatedarea, drier than the surrounding marsh, allowing trees and other vegetation togrow. Bones also leaked phosphorus, a nutrient for plants that is otherwisescarce in the Everglades.

"This goes to show that human disturbance in the environmentdoesn't always have a negative consequence," says Gail Chmura, apaleoecologist at McGill University in Montreal, Canada, and one of the authors of the study.

Chmura will be presenting her research tomorrow, Tuesday 22 March, atthe American Geophysical Union's Chapman Conference on Climates, PastLandscapes, and Civilizations. About 95 scientists have converged on Santa Fe this week todiscuss the latest research findings from archeology, paleoclimatology,paleoecology, and other fields that reveal how changes in regional and globalclimate have impacted the development and fates of societies.

In a previous scientific investigation of tree islands, MargoSchwadron, an archeologist with the National Park Service,cut through the elevated bedrock at the base of two islands and discovered thatit was actually a so-called "perched carbonate layer," because therewas more soil and a midden below. Later, a team including Chmura's graduatestudent Maria-Theresia Graf performed additional excavations in South Florida and found more of the perched carbonatelayers.

Chemical analysis of samples of these curious perched layers revealedthat they are made up partially of carbonates that had dissolved from thebedrock below, Chmura says. The layer also contains phosphorus from dissolvedbones, she adds. Her team concluded that trees are key to the formation of thislayer: During South Florida's dry season,their roots draw in large quantities of ground water but allow the phosphatesand carbonates dissolved in it to seep out and coalesce into the stone-likelayer.

The perched carbonate plays a key role in letting tree islands reboundafter fires: because it does not burn, it protects the underlying soil, and itmaintains the islands' elevation, allowing vegetation to regrow after the fire.Humans are now threatening the existence of tree islands, by cutting down trees(whose roots keep the perched layer in place) and artificially maintaining highwater levels year-round in some water control systems, which could cause thelayer to dissolve.

Chmura's team now wants to explore exactly when trees started growingon the tree islands

Giant Bunny

It has long been possible tobreed out huge rabbits and it was quite likely that on some island we would runacross a giant bunny.  That is nowaccomplished with the discovery of these fossils.

Obviously they failed to survivecontact with man, but it would have been surprising if they had.

Anyway, it is Easter and this isan appropriate tale for the time

King of Rabbits: Ancient, Gigantic Bunny Discovered

Charles Q. Choi, LiveScienceContributor

Date: 21 March 2011 Time: 03:02 PM ET

A reconstruction of Nuralagus rex in a landscape with a living Europeanrabbit Oryctolagus cuniculus in the foreground for comparison.

CREDIT: Meike Köhler 

http://www.livescience.com/13340-giant-rabbit-fossils-minorca-island.html

Just in time for Easter, the skeleton of a giant rabbit has beendiscovered, one that was once about six times the size of today's bunnies.

The fossils of the giant were discovered on the islandof Minorca off the coast of Spain,a fact reflected in the rabbit's scientific name, Nuralagus rex, "theMinorcan king of the rabbits." [Illustrationof giant rabbit]

"I needed four years to recover a good sample of N. rex bonesbecause they were in very hard red stone," paleontologist Josep Quintanaat the Catalan Institute of Paleontology in Barcelona, Spain, told LiveScience."To pull the bones out from the matrix, it was necessary to use somehundreds of liters of acetic acid, a very concentrated vinegar — very hard andpatient work! But it was worthwhile, of course."

When the bunny lived approximately 3 million to 5 million years ago, itweighed about 26 pounds (12 kilograms), about six times the size of the livingEuropean rabbit (Oryctolagus cuniculus). [Fossilsof Oldest Rabbit Relative Found]

The fact that it got so big on Minorcaseems to follow the so-called "island rule." On islands, big animalsoften get smaller, due to limited food, while small animals often get bigger,due to lack of predators.

Foot bones of Nuralagus rex, the giant rabbit whose remains werediscovered on the island of Minorca.

"For most of their over 40-million-year history, members of therabbit family have fit well within the size range exhibited by relativelywell-known modern members of the family. Now, discoveries on Minorca have addeda giant to the mix, a 25-pound, short-legged rabbit," said rabbit researcherMary Dawson at the Carnegie Museum of Natural History in Pittsburgh, who didnot take part in this study.

As big as it was, N. rex might have been easy prey today — itlost the ability to hop. The long, springy spine of a typicalmodernrabbit was lost in N. rex, replaced by a short, stiff spine thatwould make leaping difficult.

"I think thatN. rex would be a rather clumsy rabbit walking —imagine a beaver out of water," Quintana said.

The giant probably also had poor hearing and vision, with relativelysmall eye sockets and internal ear parts. Its senses likely deteriorated forthe same reason it got so large — it did not have predators to worry about. Assuch, it probably lacked another key trait often associated with rabbits —long ears. The bunny likely sported relatively small ears for its size.

Based on the rabbit's curved claws, the researchers suspect the animalwas most probably a digger that lived on roots and tubers it unearthed. Itsneighbors included bats, large dormice and giant tortoises.

Quintana proposes that this newfound giant might make a good mascot forthe island. "I would like to use N. rex to lure students andvisitors to Minorca," he said.

The scientists detailed their findings online today (March 21) in theJournal of Vertebrate Paleontology.